242 APPLIED BACTE BIOLOGY 



10 c.c. of a culture which had been heated for an hour at 

 70° C. The symptoms produced consisted of pains at the 

 seat of the inoculation, and a rise of temperature. The 

 highest point reached was 102° ¥., 8-5 hours after the 

 injection, which was accompanied by a slight headache 

 and a feeling of faintness. The temperature was normal 

 twenty-four hours later. The bowels remained normal ; 

 the pain at the seat of the inoculation was mostly felt 

 the next morning whilst getting up from bed. A small 

 nodule remained at the seat of the inoculation, but was 

 rapidly absorbed.' The injection of a killed culture — 

 which, to all intents and purposes, is simply a solution 

 of the toxin secreted by the bacillus — could not produce 

 plague, so that from the experiment above mentioned it 

 will be seen that the inoculation would be comparatively 

 harmless ; but before this method could be universally 

 adopted, it would be necessary to ascertain the exact dose 

 to produce immunity, how long after injection the highest 

 point of resistance is reached, and, finally, for how long the 

 immunity thus conferred lasts. 



Preventive Measures. — These should be such as would 

 be adopted in the event of an outbreak of cholera. Dr. 

 Atkinson, Principal Civil Medical Officer of Hong Kong, 

 in a report to the Government on the plague, dated 1897, 

 states that the general conclusions to be drawn from the 

 experiences of 1894-1896 are as follows : 



1. That the occurrence of plague is favoured by : 



(a) Long prevalence of drought or of abnormally low 

 rainfall. 



(6) Atmospheric temperature below 82° P. 



(c) Absence of sunshine. 



(d) General insanitary conditions, such as obstruction to 

 the free access of light and air to domestic dwellings. 



